we have designed a board based on the XL216 processor with a XSYS connector on the board. We have only used the JTAG lines (nRST, TMS, TCK TDI and TDO), not XLINK but I think this OK, since we have older designs with XS1-L16 processors working like this since years.

Problem : we are unable to start the debugger when XTAG is connected to the processor.

When we open the debugger configuration window, we see "XMOS XTAG-3 connected to O[0][NWVVdfTZ]", so we assume that the XTAG is able to see the processor.

However, when we try to launch the application by the debugger, it stops immediately with the following error "Launching tester.xe has encountered a problem. Load failed"A click on "details" button leads nowhere : "Load failed Please refer to http://www.xmos.com/knowledgebase/tools for more details" which is a page which does not exist anymore on XMOS website

We have tried to change the JTAG speed with different values : no success.Power supplies are OK, the sequencing seems correct (a NCP303LSN30 to activate the 1V0 regulator and a NCP303LSN09 to activate the reset line)

Have you tested more than one of this custom design? Do all tested pcbs behave the same?

I will make an excerpt of the schematics (the whole design is quite big and there are confidential things on it).

We have two prototypes for now and the second one does not start at all, the reset line remains active (we think we found the issue for this one from a bad component). I will make a test with this one and check if it behaves the same or not

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Update..

Review your clock value (section 7 of datasheet) vs. Internal Pll use. Are you using usb on this design? If yes, from memory, believe you will require 24 mhz or some multiple of this value. The 16 mhz is not a standard value for xmos with usb enabled unless this clock is applied with an external Pll? With the xl prefixed cpu assuming there is no usb port in use for your design.

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Hi Mon2,

we already checked all these points, that's why I decided to come here to get some support. The only point we can't really check is if the pad is correctly soldered or not (we don't have an X-RAY machine here), but the board has been made in a factory and they know their job, so we can trust them (and moreover, we see some solder going thru some vias)

Here are the schematics of the power supply and reset sections related to the XMOS

Benoit

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Review your clock value (section 7 of datasheet) vs. Internal Pll use. Are you using usb on this design? If yes, from memory, believe you will require 24 mhz or some multiple of this value. The 16 mhz is not a standard value for xmos with usb enabled unless this clock is applied with an external Pll? With the xl prefixed cpu assuming there is no usb port in use for your design.

No, there is no USB in our design. We checked already the clock frequency : 16MHz is normally valid, the XL216 datasheet says that allowed frequency is 9 to 25MHz (giving 144MHz to 400MHz boot frequency).